A 75-year-old white man with a 4-year history of chronic myeloproliferative disease suddenly began vomiting and had generalized bone pain, weakness, and a temperature of 38°C. Physical examination revealed that he had more than 50 white, nontender, moderately firm, subcutaneous nodules, measuring 5 to 25 mm in diameter, on the chest wall, abdomen, back, and extensor surface of the left leg (Figure 1 and Figure 2). There were several ecchymoses on the left shoulder and arm. No lesions were observed on the mucous membranes. A 3-mm punch biopsy specimen was sent for histopathological examination (Figure 3 and Figure 4).